We will continue investigations of the mechanisms which underlie the maintenance of immunologic self-tolerance and the induction of autoimmune disease, employing experimental allergic encephalomyelitis (EAE) as a model system. These studies will include further characterization of suppressor T cells which regulate the development of EAE and elucidation of the mechanism through which they exert this suppressor function. Concomitantly, the effect of these suppressor T cells on other in vivo and in vitro manifestation of the cell-mediated immune response will be determined. Experiments will be initiated to define the effector mechanism responsible for the induction of EAE by T lymphocytes.